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function DI_MNum($Mon, $Year) {
		$nn = Array(31,28,31,30,31,30,31,31,30,31,30,31);
		$x = 28;
		$y = (Round($Year/4))*4;
		if ($y==$Year) $x = 29;
		$ret = $nn[$Mon];
		if ($Mon==1) $ret = $x;
		return $ret;
	}

	function DI_FirstDay($Mon,$Year) {
		$x0 = 365;
		$Y = $Year-1;
		$days = $Y*$x0+floor($Y/4)+6;
		for ($j=0; $j<$Mon; $j=$j+1) {
			$days = $days+DI_MNum($j,$Year);
		}
		$week = $days-(7*Round(($days/7)-0.5));
		return $week;
	}

	function even_week($Day,$Mon,$Year) {
		$x0 = 365;
		$Y = $Year-1;
		$days = $Y*$x0+floor($Y/4)+6;
		for ($j=0; $j<$Mon; $j=$j+1) {
			$days = $days+DI_MNum($j,$Year);
		}
		$days = $days + $Day;
		$weeks = ceil($days/7);

		$res = false;
		if (2*ceil($weeks/2) == $weeks) $res = true;
		return $res;
	}